KR101423248B1 - Light source unit, backlight assembly having the same, and liquid crystal display having the same - Google Patents

Abstract

The present invention relates to a light source unit which is excellent in efficiency of a light source and can be manufactured with a small material cost, a backlight assembly including the light source unit, and a liquid crystal display device including the same.

A light source unit according to the present invention includes: a light source; And a columnar light pipe including a plurality of grooves having different lengths from which light emitted from the light source is incident.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light source unit, a backlight assembly including the light source unit, and a liquid crystal display device including the light source unit. BACKGROUND OF THE INVENTION [0001]

1 is an exploded perspective view illustrating a liquid crystal display device according to a first embodiment of the present invention.

2 is a cross-sectional view illustrating a liquid crystal display device according to I-I 'shown in FIG.

FIG. 3 is a perspective view showing the light source unit and the light guide plate shown in FIG. 1. FIG.

4 is a front view showing the light source unit shown in Fig.

5 is an exploded perspective view illustrating the light source shown in Fig.

6 is a cross-sectional view illustrating a light source according to II-II 'shown in FIG.

Fig. 7A is an enlarged cross-sectional view of the portion c of the light pipe shown in Fig. 4, and Fig. 7B is an enlarged view of the portion c of the light pipe shown in Fig. 4 according to the second embodiment of the present invention And Fig. 7C is a cross-sectional view showing the light pipe according to III-III 'shown in Figs. 7A and 7B.

Fig. 8A is an enlarged cross-sectional view of a portion c of the light pipe shown in Fig. 4 according to the third embodiment of the present invention, Fig. 8B is a cross- 8C is a cross-sectional view showing the light pipe according to IV-IV 'shown in Figs. 8A and 8B. Fig.

9 is a plan view for explaining that light emitted from the light source portion is emitted through an emission pattern of the light pipe.

10 is an exploded perspective view illustrating a liquid crystal display device according to a sixth embodiment of the present invention.

11 is an exploded perspective view illustrating a liquid crystal display device according to a seventh embodiment of the present invention.

≪ Brief Description of Drawings &

10: Top chassis 20: Liquid crystal display panel

21: Color filter substrate 23: Thin film transistor substrate

60: mold frame 70: optical sheet

80: light guide plate 90: light guide tube

91: Emitter 93: Emission pattern

95: Light source unit 100: Light source unit

103: housing 105: hole

107: power supply board 110: light emitting diode package

113: substrate 115: lens part

117: light emitting diode 120: light pipe cover

130: reflective sheet 140: bottom chassis

200: liquid crystal display

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light source unit, a backlight assembly including the same and a liquid crystal display including the same, and more particularly, to a light source unit having excellent efficiency of a light source and capable of being manufactured with a small material cost and a backlight assembly including the same and a liquid crystal display .

2. Description of the Related Art Liquid crystal displays (LCDs) are typical of flat panel displays and have advantages such as small size, light weight, and low power consumption compared to cathode ray tubes. Therefore, the liquid crystal display device has been widely applied to the industry in general, for example, the computer industry, the electronic industry, and the information communication industry due to such unique advantages.

BACKGROUND ART [0002] In recent years, in order to satisfy the object of light weight shortening of a liquid crystal display device, there has been a tendency to continue research on each member constituting a liquid crystal display device such as a backlight, a connector, a printed circuit board, to be.

The liquid crystal display includes a liquid crystal display panel, a backlight assembly for providing light to the liquid crystal display panel, and a driving circuit for generating various signals required for the liquid crystal display panel to implement an image. The liquid crystal display includes a liquid crystal display panel, a mold frame for housing the backlight assembly, and a bottom chassis.

2. Description of the Related Art In recent years, a light source of a liquid crystal display device is classified into a cold cathode fluorescent lamp (CCFL) and a light emitting diode (LED). Currently, a lot of fluorescent lamps are used, but in recent years, the use of light emitting diodes has also been increasing. When a light emitting diode is used as a light source of a liquid crystal display, a plurality of light emitting diodes should be used in place of a fluorescent lamp in order to convert a light emitting diode, which is a point light source, into a linear light source or a planar light source.

When such a light emitting diode is used, it is advantageous in that it has a thin shape and a high color reproduction, but has a problem of heat generation, poor life and high material cost. Accordingly, since a plurality of light emitting diodes are used as a light source of a liquid crystal display device, a large amount of material cost is consumed in manufacturing a backlight assembly.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a light source unit including a light pipe and a light source, which is excellent in efficiency of a light source and can be manufactured with a small material cost, a backlight assembly including the light source unit, and a liquid crystal display device including the same.

According to an aspect of the present invention, there is provided a light source unit comprising: a light source; And a columnar light pipe including a plurality of grooves having different lengths from which light emitted from the light source is incident.

Further, the groove is lengthened away from the light source.

According to an aspect of the present invention, there is provided a backlight assembly comprising: a light source unit for emitting light for emitting light; And a light guide plate for guiding light emitted from the light source unit, the light source unit having a columnar shape and having an emission pattern on a surface facing the light guide plate; And a light source unit coupled to at least one end of the light guide tube and configured to emit light into the light guide tube.

On the other hand, the emission pattern is a groove formed in parallel with both ends.

The cross-section of the groove is V-shaped.

Further, the grooves are deepened from both ends of the light pipe to the center.

On the other hand, the grooves are longer toward the center than the both ends of the light pipe.

The light source unit may include a housing having an insertion hole to which the light pipe is connected at one end; A light emitting diode package coupled to the other end of the housing and configured to emit light; And a power board formed at a lower end of the housing and supplying power to the light emitting diode.

According to an aspect of the present invention, there is provided a liquid crystal display device including: a liquid crystal display panel displaying an image; A driving circuit for driving the liquid crystal display panel; A light source unit formed below the liquid crystal display panel and emitting light; And an optical sheet formed under the liquid crystal display panel, wherein the light source unit comprises: a light source; And a columnar light pipe including a plurality of grooves having different lengths from which light emitted from the light source is incident.

Further, the groove is lengthened away from the light source.

Other technical objects and advantages of the present invention will become apparent from the description of preferred embodiments of the present invention with reference to the accompanying drawings.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to FIGS. 1 to 11. FIG.

FIG. 1 is an exploded perspective view illustrating a liquid crystal display device according to a first embodiment of the present invention, and FIG. 2 is a cross-sectional view illustrating a liquid crystal display device according to I-I 'shown in FIG.

1 and 2, the liquid crystal display 200 includes a top chassis 10, a liquid crystal display panel 20, a driving circuit, a mold frame 60, a backlight assembly, and a bottom chassis 140.

The top chassis 10 is disposed at an upper portion of the liquid crystal display panel 20 and protects the liquid crystal display panel 20 and the backlight assembly from external shocks and is provided at the center thereof so that the display area of the liquid crystal display panel 20 can be exposed. And has openings.

The liquid crystal display panel 20 includes a color filter substrate 21, a thin film transistor substrate 23 formed at a position corresponding to the color filter substrate 21, and a thin film transistor substrate 23 between the color filter substrate 21 and the thin film transistor substrate 23 And a liquid crystal for controlling the light transmission amount.

The color filter substrate 21 includes a black matrix formed in a matrix form on an upper substrate such as a glass and blocking light, an red, green, and blue color filters formed in a region partitioned by the black matrix to implement color, A color filter array is formed on the upper substrate including a common electrode for applying a common voltage to the liquid crystal and an upper alignment film applied for liquid crystal alignment on the common electrode.

The thin film transistor substrate 23 includes thin film transistors (TFTs) formed on pixel regions defined by intersections of data lines and gate lines formed so as to cross each other with a gate insulating film interposed therebetween on a lower substrate such as glass, : TFT), a pixel electrode for applying a pixel voltage to the liquid crystal, and a lower alignment film coated on the pixel electrode for liquid crystal alignment are formed on the lower substrate. The thin film transistor (TFT) has a gate electrode connected to the gate line, a source electrode connected to the data line and surrounding a part of the drain electrode, and a drain electrode facing the source electrode and connected to the pixel electrode. Such a thin film transistor (TFT) is used as a switching element.

A polarizing plate may be attached to the lower surface of the thin film transistor substrate 23 and the color filter substrate 21. In general, a polarizing plate formed on the thin film transistor substrate 23 and a polarizing plate formed on the color filter substrate 21 are attached so as to be perpendicular to each other. It is also possible to attach the polarizing plate formed on the thin film transistor substrate 23 and the polarizing plate formed on the color filter substrate 21 in parallel with each other.

The driving circuit unit includes a gate driver integrated circuit (IC) 43 for driving the gate lines of the liquid crystal display panel 20, a data drive IC 53 for driving the data lines of the liquid crystal display panel 20 ). The driving circuit unit includes a timing control unit, a power supply unit, and various circuit elements, and generates various signals necessary for realizing an image. The timing control unit, the power supply unit, and various circuit elements are attached to printed circuit boards (PCBs) 45 and 55.

The various signal circuits on the gate printed circuit board 45 and the data printed circuit board 55 are connected to the gate line and the data line through the gate tape carrier package (TCP) 41 and the data tape carrier package 51 And is electrically connected. In addition, a power supply unit and a timing control unit mounted on the printed circuit boards 45 and 55 generate control signals and power supply signals using various electrical signals from the outside.

The mold frame 60 is formed of a mold material. The lower surface of the mold frame 60 supports the reflective sheet 130, the light guide plate 80, the light source unit 95 and the optical sheet 70. The upper surface of the mold frame 60 is supported by the liquid crystal display panel 20). The upper / lower / left / right sides of the mold frame 60 may be formed to be equal to or lower than the laminated height of the reflective sheet 130, the light guide plate 80, and the optical sheet 70.

The backlight assembly includes a light guide plate 80, an optical sheet 70, a light source unit 95, and a reflective sheet 130.

The light guide plate 80 converts the luminous source emitted from the light source unit 95 into a planar light source and transmits it to the liquid crystal display panel 20. Specifically, the light guide plate 80 is a transparent acrylic material having a thickness of about several millimeters to uniformly transmit light from the light source unit 95 to a screen display area. On the lower surface, a plurality of A dot or a V-shaped hole (not shown) is formed. The light guide plate 80 is formed to have a size corresponding to the liquid crystal display panel 20.

The optical sheet 70 allows the light emitted from the light guide plate 80 to enter the liquid crystal display panel 20. To this end, the optical sheet 70 is composed of a diffusion sheet 71 for diffusing light incident from the light guide plate 80 and a prism sheet 73 for vertically emitting light incident from the diffusion sheet 71 . The diffusion sheet 71 and the prism sheet 73 are formed by appropriately combining two or three sheets. The optical sheet 70 is provided on the diffusion sheet 71 or the prism sheet 73 to protect the sheets sensitive to dust or scratch and to prevent the sheets from flowing when the backlight assembly is only transported And a protective sheet 75. The optical sheet 70 vertically generates light emitted from the light guide plate 80 and enters the liquid crystal display panel 20, thereby improving light efficiency.

The light source unit 95 includes a light guide tube 90 and a light source unit 100. The light source unit 95 is installed on the side surface of the light guide plate 80 provided in parallel with the liquid crystal display panel 20. An edge-lighting method is used in which the light emitted from the light source unit 95 is incident on the liquid crystal display panel 20 by the light guide plate 80. [

On the other hand, the light guide tube 90 is preferably formed in a columnar shape. In this embodiment, the light pipe 90 of a cylindrical shape is described, but the present invention is not limited thereto and includes a columnar structure such as a square column. Further, the light source unit 95 is formed by being wrapped by the light pipe cover 120. [ The light guide tube cover 120 is made of a material having a high reflectance or has a structure in which a reflective member is coated on a cover surface covering the light guide tube 90 so that the light generated in the light guide tube 90 is directed toward the light guide plate 80 Thereby improving the efficiency of light.

The light guide tube cover 120 is formed to surround the light guide tube 90. The light guide tube cover 120 is disposed on the light guide plate 80 so as to surround the remaining portion of the outside of the light guide tube 90 except for the direction of the light guide plate 80. The light guide tube cover 120 is disposed at a predetermined distance from the light guide tube 90, and a reflection film is formed on the inner side thereof. The reflective film may be formed by coating a reflective material on the inner side of the light pipe cover 120, or by attaching a reflective sheet. Further, one side of the reflective sheet 130 may be folded into a light pipe cover 120 and used as a reflective film.

The reflective sheet 130 serves to reduce light loss by re-reflecting the light incident on the light guide plate 80 toward the light guide plate 80 through the back surface of the light guide plate 80 by using a plate having a high light reflectance. To this end, the reflective sheet 130 is coated with a reflective member having a high reflectance on the base material. Here, the base material is mainly made of brass, aluminum (Al), polyethylene terephthalate (PET) and steel use stainless (SUS). Reflective materials mainly include silver (Ag) and titanium do.

The bottom chassis 140 accommodates the backlight assembly and includes a mold frame 60 disposed on the front side of the bottom chassis 140 and an edge of the backlight assembly and a liquid crystal display panel 20).

Hereinafter, the light source unit according to the first embodiment of the present invention will be described in more detail with reference to FIGS. 3 to 6. FIG.

FIG. 3 is a perspective view showing the light source unit and the light guide plate shown in FIG. 1, and FIG. 4 is a front view showing the light source unit shown in FIG.

3 and 4, the light source unit 95 includes a light source unit 100 for generating light and a light guide tube 90 for emitting light emitted from the light source unit 100. [

The light source unit 100 includes a housing 103, a light emitting diode package 110, a power source substrate 107, and an electrode 109. The light source unit 100 is formed at both ends of the light guide tube 90 to transmit light to the light guide tube 90.

The housing 103 includes a hole 105 to which the light emitting diode package 110 and the light pipe 90 are coupled as shown in FIG. 6, a light emitting diode package 110 is coupled to one end of the hole 105 of the housing 103 and a light guide plate is coupled to the other end of the hole 105 of the housing 103 . The housing 103 is made of a plastic material and generates heat in the light emitting diode package 110, thereby forming heat-resistant plastic. For example, the housing 103 preferably uses a heat resistant phenolic resin.

The light emitting diode package 110 includes a substrate 113, a light emitting diode 117, and a lens unit 115. The light emitting diode package 110 is mounted on one end of the housing 103 as shown in FIG.

The light emitting diode 117 generates light and is transmitted to the light pipe 90 through the lens unit 115. The light emitting diode 117 is mounted on the substrate 113. The lens portion 115 is formed to cover and protect the light emitting diode 117 and is bonded and bonded to the substrate 113. As shown in FIGS. 5 and 6, the lens unit 115 is formed of a convex lens that collects light generated in the light emitting diode 117. In addition, the lens unit 115 may be formed of a concave lens that disperses light generated in the light emitting diode 117. Meanwhile, the lens unit 115 may be formed of a transparent plastic cap or silicon to surround the light emitting diode 117.

The power supply board 107 is formed at a lower portion of the housing 103 and supplies power to the light emitting diode 117. An electrode 109 is mounted on the power supply board 107. The substrate 113 on which the light emitting diode 117 is mounted is connected to the electrode 109 through a lead wire (not shown) to supply power to the light emitting diode 117.

The light guide tube 90 is disposed on one side of the light guide plate 80 as shown in Fig. The light guide tube 90 changes the point light source irradiated from the light source unit 100 to a light source and transmits the light to the light guide plate 80. As shown in FIG. 4, light sources 100 are formed at both ends of the light guide tube 90 to supply light to the light guide tube 90. The light guide tube 90 is formed in a cylindrical shape and made of a transparent polymer material. For example, the light guide tube 90 may be formed of any one of poly (methyl methacrylate) (PMMA), polycarbonate (PC), and polyethylene terephthalate (PET).

The light guide tube 90 includes an output portion to which the light irradiated from the light source unit 100 is irradiated. A plurality of outgoing patterns are formed in an area facing the light guide plate (80).

Referring to Fig. 7A, an output portion 91 of the light pipe 90 includes a plurality of output patterns 93. Fig. It is preferable that the emission pattern 93 is formed in a groove and is formed in parallel with both ends e of the light pipe 90. The length l of the groove is preferably increased from both ends e to the center c of the light guide tube 90. The larger the length l of the groove is, the larger the reflection amount is. The intensity of the light irradiated from the light source unit 100 becomes smaller at the center c of the light guide tube 90 so that the length l of the groove is made larger so that the reflectance at both ends e and c of the light guide tube 90 . Accordingly, the light guide tube 90 transmits uniform light to the light guide plate.

It is preferable that the grooves are inclined with respect to the ends e of the light pipe 90 as shown in FIG. 7B, and the lengths 1 of the grooves are different from each other. On the other hand, the groove is formed in a V shape as shown in FIG. 7C, and the depth d of the groove is formed to have the same depth d.

8A, the length 1 of the groove is formed to be parallel to both ends e of the light pipe 90 with the same length. 8B, the length 1 of the groove is formed to be inclined with both ends e of the light pipe 90 with the same length. On the other hand, the depth d of the groove increases from both ends e of the light pipe 90 to the center c as shown in Fig. 8C. The larger the depth d of the groove, the larger the reflection amount. The intensity of the light irradiated from the light source unit 100 becomes smaller at the center of the light pipe 90 so that the depth d of the groove is increased so that the reflection amounts of both ends e and c of the light pipe 90 are equal And transmits uniform light to the light guide plate.

9 is a plan view for explaining that light emitted from a light source is emitted through an emission pattern of a light pipe.

9, the light emitted from the light emitting diode 117 of the light source unit 100 is reflected through the emission pattern 93 of the light pipe 90 and transmitted to the light guide plate 80. The light emitted from the light emitting diode 117 formed on the substrate 113 of the light emitting diode package 110 is reflected on one side of the outgoing pattern 93 formed on the outgoing portion of the light pipe 90, Lt; / RTI > The light guide plate 80 transmits the supplied light to the liquid crystal display panel. Then, the light guide tube 90 emits the point light source irradiated by the light emitting diode 117 to the linear light source.

10 is an exploded perspective view illustrating a liquid crystal display device according to a sixth embodiment of the present invention.

The liquid crystal display device 200 shown in Fig. 10 has the same components as those of the liquid crystal display device 200 shown in Fig. 1 except that the light source units 95 are disposed on both sides of the light guide plate 80 do. Accordingly, detailed description of the same constituent elements will be omitted.

10, the light source unit 95 includes a light guide tube 90 having a cylindrical shape and emitting light radiated therein to a source of light, a light source unit 90 disposed at both ends of the light guide tube 90, 100). The light source unit 95 is disposed on both sides of the light guide plate 80 to supply light to the liquid crystal display panel 20 and an emission pattern formed in the light exit portion of the light guide tube 90 in the direction of the light guide plate 80. Specifically, the light generated in the light emitting diode package is transmitted to the light guide plate 80 through the emission pattern, and the light guide plate 80 transmits the emitted light to the liquid crystal display panel 20.

11 is an exploded perspective view illustrating a liquid crystal display device according to a seventh embodiment of the present invention.

The liquid crystal display shown in Fig. 11 has the same components as those of the liquid crystal display shown in Fig. 1, except that the light source unit is formed below the optical sheet 70. Fig. Accordingly, detailed description of the same constituent elements will be omitted.

Referring to FIG. 11, the light source unit 95 includes a light guide tube 90 and a light source unit 100 that supplies light to the light guide tube 90. The optical sheet 70 is formed below the optical sheet 70 and is formed in parallel with the liquid crystal display panel 20 to transmit light directly to the liquid crystal display panel 20. Specifically, a plurality of light source units 95 are formed under the diffusion sheet 71 of the optical sheet 70 to transmit light to the liquid crystal display panel 20. An emission pattern formed on the light guide tube 90 of the light source unit 95 is formed in the direction of the diffusion sheet 71 and light generated in the light source unit 100 is transmitted to the liquid crystal display panel 20. [

As described above, the light source unit, the backlight assembly including the light source unit, and the liquid crystal display including the light source unit according to the present invention include a light source and a light guide tube for converting the light generated from the light source into a light source.

Such a light source unit can be manufactured by using a light emitting diode instead of a plurality of light emitting diodes and a light emitting diode with a small material cost. In addition, a uniform luminance can be achieved by an emission pattern formed on the light pipe, and the luminance unbalance, which is a problem in using a light emitting diode, can be solved. Such a liquid crystal display device can operate with less power consumption by reducing the number of light emitting diodes.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention.

Claims (10)

delete delete A light source unit for irradiating light; And a light guide plate for guiding light emitted from the light source unit, The light source unit A light guide tube having a columnar shape and an emission pattern on a surface facing the light guide plate; And light sources coupled to both ends of the light guide tube and configured to irradiate light into the light guide tube, Wherein the emission pattern is deepened toward the center at both ends of the light pipe, and has grooves provided at both ends and sloped. delete The method of claim 3, Wherein the groove has a V-shaped cross-section. delete The method of claim 3, Wherein the groove is longer toward the center from both ends of the light pipe. The method of claim 3, The light source unit A housing having an insertion hole to which the light pipe is connected at one end; A light emitting diode package coupled to the other end of the housing and configured to emit light; And And a power board formed at a lower end of the housing to supply power to the light emitting diode. A liquid crystal display panel for displaying an image; A driving circuit for driving the liquid crystal display panel; A light source unit formed below the liquid crystal display panel and emitting light; And an optical sheet formed under the liquid crystal display panel, The light source unit A light source for generating the light; And a columnar light guide tube having a plurality of grooves having a length which are different from each other and in which light emitted from the light source is incident, Wherein the grooves are deepened from both ends of the light pipe to the center, and the grooves are inclined at both ends. 10. The method of claim 9, And the groove becomes longer as the distance from the light source increases.

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